[Feature]: ADK 2.x Support

### Pre-flight Checklist

- [x] I have searched existing issues and this hasn't been requested yet.

### Problem or Motivation

Hi,

After ADK 2.1 stable version release, is there any plans for supporting it?

Features like RequestInput, Workflows, Collaborative Mode (subagents task and single_turn mode).

Thanks

### Proposed Solution

for request input it would be great if we could have a hook to handle the requestinput in the front end better.

### Alternatives Considered

_No response_

### Additional Context

_No response_